Grouting composition containing cupric acrylate

ABSTRACT

An aqueous solution of 
     (a) acrylic acid; 
     (b) cupric acrylate; 
     (c) methylene bis acrylamide; and 
     (d) a water-soluble polymerization catalyst which also is a reducing agent; 
     with the ratio of (a) to (b) being between 10:0.1 to 10:1.5, which solution forms a water resistant gel.

INTRODUCTION

It is now known that soil can be stabilized by treating it with aqueoussolutions which contain methylene-bis-acrylamide and water-soluble vinylmonomers such as acrylamide and water-soluble salts of acrylic acid,particularly sodium acrylate. These solutions are polymerized in thepresence of a suitable catalyst to form water-insoluble gels whichconsolidate and firm up the soil. The various soil stabilizationapplications as well as the methylene-bis-acrylamide solutions and gelsformed therefrom are described in U.S. Pat. No. 2,801,984, thedisclosure of which is incorporated herein by reference.

Commercially, grouting is accomplished using methylene-bis-acrylamidewith acrylamide. Soils treated with solutions of these two monomerswhich are subsequently polymerized in contact with the soil producedense, friable masses of soil which can be chipped or broken. Whensodium acrylate is substituted for acrylamide in making these gels, theresultant gels tend to become less rigid as they are exposed tomoisture, thus rendering their usability limited in treating soils.

THE INVENTION

This invention comprises an aqueous solution of

(a) acrylic acid;

(b) cupric acrylate;

(c) methylene bis acrylamide; and

(d) a water-soluble polymerization catalyst which also is a reducingagent;

with the ratio of (a) to (b) being between 10:0.1 to 10:1.5, whichsolution forms a water resistant gel.

The concentration of the above ingredients in water used to produce thegels of the invention may vary although approximately 10% acrylic acid,0.1 up to about 1.5% cupric acrylate, and about 1% methylene bisacrylamide give optimum results. Slightly lower or greater dosages maybe used. The soils treated with these solutions and gelled are resilientand have a different character than the methylene bis acrylamide treatedsoils.

As indicated, one of the most interesting and unique features of theinvention is that when cupric acrylate is used, it is necessary toutilize a water-soluble polymerization catalyst which is also a reducingagent. Such catalysts are ammonium, sodium or potassium bisulfate.

EXAMPLES

To illustrate the invention, the following are presented by way ofexamples. In the Table set forth below, the penetration values wereobtained using a standard grease penetrometer. Any value below 250 isconsidered acceptable.

It should be particularly noted that very little water is picked up bythe gels based on percent by weight increase after standing in water forprolonged periods of time. This is surprising since mostacrylate-methylene bis acrylamide gels pick up substantial quantities ofwater under the test conditions used in the Table.

                                      TABLE I                                     __________________________________________________________________________    Acrylic                                                                            Acrylate                        Water Pick-Up                            Acid Salt Methylene bis                                                                             Water                                                                             Set Time   (% increase)                             %    %    Acrylamide                                                                           Catalyst                                                                           %   (sec)                                                                              Penetration                                                                         24 hours.                                                                         120 hrs.                             __________________________________________________________________________    10   0.1 Cu.sup.2+                                                                      1.0    R*   88.9                                                                              240  205    7.2                                                                              23                                   10   0.2 Cu.sup.2+                                                                      1.0    R    88.8                                                                              300  225   18.1                                                                              49                                   10   0.3 Cu.sup.2+                                                                      1.0    R    88.7                                                                              600  --                                             10   0.4 Cu.sup.2+                                                                      1.0    R    88.6                                                                              900  --                                             __________________________________________________________________________     *R = 0.5% NaHSO.sub.3 was used as the catalyst and reducing agent.       

I claim:
 1. An aqueous solution of(a) acrylic acid; (b) cupric acrylate;(c) methylene bis acrylamide; and (d) a water-soluble polymerizationcatalyst which also is a reducing agent;with the ratio of (a) to (b)being between 10:0.1 to 10:1.5, which solution forms a water resistantgel.